lib/crypto: tests: Drop the default to CRYPTO_SELFTESTS

lib/crypto: tests: Drop the default to CRYPTO_SELFTESTS

Defaulting the crypto KUnit tests to KUNIT_ALL_TESTS || CRYPTO_SELFTESTS
instead of simply KUNIT_ALL_TESTS was originally intended to make it
easy to enable all the crypto KUnit tests.  This additional default is
nonstandard for KUnit tests, though, and it can cause all the KUnit
tests to be built-in unexpectedly if CRYPTO_SELFTESTS is set.  It also
constitutes a back-reference to crypto/ from lib/crypto/, which is
something that we should be avoiding in order to get clean layering.

Now that we provide a lib/crypto/.kunitconfig file that enables all
crypto KUnit tests, let's consider that to be the supported way to
enable all these tests, and drop the default of CRYPTO_SELFTESTS.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260317040626.5697-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>